1. Field of the Invention
This invention relates to bone plates for internal fixation of fractures of the femur bone. In particular the present invention relates to sliding screw or impaction nail plates particularly useful for repair of a fractured femur. The invention is particularly useful for providing more secure support and consolidation of femur bone fragments from intertrochanteric and subtrochanteric fractures.
2. Prior Art
A wide variety of implantable bone plates are known in the art for support and fixation of bone fracture. Since the breakage or fracture of bones in the body is not limited to size of person or bone implantable plates of different sizes and shape need be made readily available. This calls for the carrying of a large inventory of plates and screws for the various bones expected to be fractured and in need of fixation.
There are approximately 150,000 to 200,000 hip fractures each year in the United States alone. Approximately half of these hip fractures are intertrochanteric and/or subtrochanteric fractures. Quite often the plate implants that are available for repair of such fractures, such as sliding hip screw plates or impaction nail plates do not provide for sufficient attachment to secure all the bone fragments.
There has been, therefore, a need for a means or method for improving currently used implantable plates. The present invention addresses that need.
U.S. Pat. No. 4,488,543 appears to address the problem of preventing screw back out, that is, preventing the screws holding screw plates to the bone, from backing out of the bone. The structure taught in this patent addresses the security of screws attaching the plate to the bone but fails to provide for extended coverage of bone area as needed and fails to provide for holding bone fragments where required.
Other patents teach structure of implant plates, such as pronged plates for resetting fractured bones, as in U.S. Pat. No. 4,565,193 and the pronged bone joining plate taught in U.S. Pat. No. 4,651,724 and the elongated rod bone plate of U.S. Pat. No. 4,573,458, but none of these patents address the problems of providing more direct stability and security for the bone fragments of the fractured bone.